This invention relates to a method for coating an adhesive agent to at least one of the opposite surfaces of a plate material composed of a foamed material and a coating apparatus suited for carrying out the coating method.
In the coating method and the coating apparatus of the present invention, a plate material as an object for coating thereon an adhesive agent is a plate material of the type composed of a foamed material having open cells such as a polypropylene foam or a urethane foam, and in which when the compressing force is released after the plate material is widthwise compressed, for example, by ΔT, the plate material is immediately returned to this original state by ΔT1 (<ΔT) of all the compression deformation portion ΔT but the remaining compression deformation portion ΔT2 (=ΔT−ΔT1) is gradually returned to its original state taking time, for example, more than a few minutes.
In general, a roof lining material of an automobile comprises a core material, a plate material composed of a urethane foam fixed by bonding to a surface of the core material facing the inside of the automobile, and a skin fixed by bonding to a surface of the plate material facing the inside of the automobile. In manufacturing such lining material, after an adhesive agent is coated to both of the front surface and the back surface of the plate material, the core material and the skin are bonded to the respective surfaces of the plate material.
Conventionally, in coating an adhesive agent to both the front surface and the back surface, a pair of coating rolls are used as disclosed in the official gazette of Japanese Patent Application Laid-Open No. 2002-52508. The pair of coating rolls are vertically spacedly arranged in parallel relation with their longitudinal direction directing in a horizontal direction and driven for rotation in opposite directions to each other. Moreover, an adhesive agent supplied from an adhesive agent supplying apparatus is coated to the entire outer peripheral surface of each coating roll. Accordingly, when a plate material is passed between the pair of coating rolls, the adhesive agent is coated to both the front surface and the back surface.
Since the plate material used as a top lining material of an automobile is large in length and width, the plate material is comparatively greatly different in thickness at its various parts. For this reason, when an adhesive agent is coated to the plate material by the coating rolls, the adhesive agent coated to the various parts of the plate material becomes greatly irregular in thickness. That is, there is a problem that a large quantity of an adhesive agent is coated to the thick part of the plate material, while a small quantity of an adhesive agent is coated to a thin part of the plate material.